During the yarn manufacturing process, yarn or other textile packages are formed by wrapping yarn onto yarn carriers or tubes that are rotated at high speeds, sometimes in excess of 8,000 rpm. Typically, the yarn carrier is rotated by a drive mechanism that includes a driven roller which contacts the outer surface of the carrier at the start of the wrapping and drives the carrier through frictional engagement between the driven roller and the carrier. As layers of yarn are wrapped onto the carrier, the driven roller moves radially outward from the carrier, maintaining frictional contact with the outer layer of yarn. A pick-up groove is usually provided at one end of the tube for capturing the yarn and initiating the wrapping of the yarn onto the tube.
Often the carrier or tube is formed by spirally winding a number of plies together. Constructing a carrier or tube which can withstand the significant forces associated with the wrapping of yarn, especially carpet yarn fibers, at high speed has proven challenging. The assignee of the present invention has disclosed several techniques and structures for addressing this challenge in U.S. Pat. No. 4,462,556 to Graham Jr., U.S. patent No. RE33,060 to Cunningham et al., U.S. Pat. No. 5,505,395 to Qiu et al., U.S. Pat. No. 5,393,582 to Wang et al., and U.S. Pat. No. 5,472,154. The entire contents of each preceding patent are hereby incorporated by reference.
A wide variety of yarns and other textile materials are used to produce an array of textile products. Unfortunately, many textile yarns are not easily distinguishable from one another. Therefore, one important feature of a yarn tube is the means for identifying the particular type of yarn on the tube without a detailed inspection of the yarn. A visual symbol or identification mark is often applied to the rim of the tube, above the yarn wrapped thereon. These markings may be a printed symbol on the ends of the tube. A particularly useful means for yarn identification is to color code the carriers with one or more colored bands on their outer peripheral surfaces. Multiple bands are preferred because they can convey more information than a single colored band. For example, one band may be used to designate the yarn material and another may be used to designate the denier of the yarn. Moreover, providing various combinations of colors allow a greater number of yarns to be identified than if one band was used.
Placing yarn identifying markings on the outer peripheral surface of the carrier exposes them to significant wear from frictional contact with the driven roller during the start of the wrapping operation, the wrapping of the first layer of yarn onto the carrier, or handling of the carrier while empty. The wearing away of the markings can produce dust that could contaminate the yarn and could collect on the parts of the wrapping machine, which would require more frequent maintenance and increased risk of failure. In addition, after prolonged use, the markings may wear away completely, requiring the markings to be reapplied or new carriers to be provided more often than desired.
Another marking technique is to color the outer layer of the tube as generally described in U.S. Pat. No. 6,851,643 to Qiu et al. and assigned to the same assignee as the present application, the entire contents of which are hereby incorporated by reference. However coloring the outer layer is expensive and sometimes interferes with the ability to construct an outer layer that can withstand the forces associated with the wrapping forces.
Therefore, a need exists for a spirally wound yarn tube or carrier with a identification feature which can withstand the forces of the yarn manufacturing process. Furthermore, it would be advantageous for such a tube to be the product of a cost effective process.